Association of MBL2 gene polymorphisms and systemic lupus erythematosus susceptibility: A meta-analysis

A Framework to Overcome Challenges in the Management of Infections in Patients with Systemic Lupus Erythematosus

Infections remain one of the leading causes of death in systemic lupus erythematosus (SLE), despite awareness of factors contributing to increased susceptibility to infectious diseases in SLE. Clinicians report challenges and barriers when encountering infection in SLE as certain infections may mimic a lupus flare. There are no evidence-based practice guidelines in the management of fever in SLE, with suboptimal implementations of evidence-based benefits related to infectious disease control and/or prevention strategies in SLE. Vigilance in identifying an opportunistic infection must be stressed when confronted by a diagnostic challenge during a presentation with a febrile illness in SLE. A balanced approach must focus on management of infections in SLE, and reduction in the glucocorticoids dose, given the need to control lupus disease activity to avoid lupus related organ damage and mortality. Clinical judgement and application of biomarkers of lupus flares could reduce false positives and overdiagnosis and improve differentiation of infections from lupus flares. Further precision-based risk and screening measures must identify individuals who would benefit most from low dose immunosuppressive therapy, targeted immune therapy, and vaccination programs.

Overview on the Link Between the Complement System and Auto-Immune Articular and Pulmonary Disease

Complement system (CS) dysregulation is a key factor in the pathogenesis of different autoimmune diseases playing a central role in many immune innate and adaptive processes. Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by ta breach of self-tolerance leading to a synovitis and extra-articular manifestations. The CS is activated in RA and seems not only to mediate direct tissue damage but also play a role in the initiation of RA pathogenetic mechanisms through interactions with citrullinated proteins. Interstitial lung disease (ILD) represents the most common extra-articular manifestation that can lead to progressive fibrosis. In this review, we focused on the evidence of CS dysregulation in RA and in ILD, and highlighted the role of the CS in both the innate and adaptive immune responses in the development of diseases, by using idiopathic pulmonary fibrosis as a model of lung disease. As a proof of concept, we dissected the evidence that several treatments used to treat RA and ILD such as glucocorticoids, pirfenidone, disease modifying antirheumatic drugs, targeted biologics such as tumor necrosis factor (TNF)-inhibitors, rituximab, tocilizumab, and nintedanib may act indirectly on the CS, suggesting that the CS might represent a potential therapeutic target in these complex diseases.

Interaction between Long Noncoding RNAs and Syncytin-1/Syncytin-2 Genes and Transcripts: How Noncoding RNAs May Affect Pregnancy in Patients with Systemic Lupus Erythematosus

BACKGROUND

Patients with systemic lupus erythematosus (SLE) often suffer from obstetric complications not necessarily associated with the antiphospholipid syndrome. These events may potentially result from the reduced placental synthesis of the fusogenic proteins syncytin-1 and syncytin-2, observed in women with pregnancy-related disorders. SLE patients have an aberrant noncoding (nc)RNA signature that may in turn dysregulate the expression of syncytin-1 and syncytin-2 during placentation. The aim of this research is to computationally evaluate and characterize the interaction between syncytin-1 and syncytin-2 genes and human ncRNAs and to discuss the potential implications for SLE pregnancy adverse outcomes.

METHODS

The FASTA sequences of the syncytin-1 and syncytin-2 genes were used as inputs to the Ensembl.org library to find any alignments with human ncRNA genes and their transcripts, which were characterized for their tissue expression, regulatory activity on adjacent genes, biological pathways, and potential association with human disease.

RESULTS

BLASTN analysis revealed a total of 100 hits with human long ncRNAs (lncRNAs) for the syncytin-1 and syncytin-2 genes, with median alignment scores of 151 and 66.7, respectively. Only lncRNAs TP53TG1, TTTY14, and ENSG00000273328 were reported to be expressed in placental tissue. Dysregulated expression of lncRNAs TP53TG1, LINC01239, and LINC01320 found in this analysis has previously been described in SLE patients as well as in women with a high-risk pregnancy. In addition, some of the genes adjacent to lncRNAs aligned with syncytin-1 or syncytin-2 in a regulatory region might increase the risk of pregnancy complications or SLE.

CONCLUSIONS

This is the first computational study showing alignments between syncytin-1 and syncytin-2 genes and human lncRNAs. Whether this mechanism affects syncytiotrophoblast morphogenesis in SLE females is unknown and requires further investigation.

MBL2 polymorphism may be a protective factor of autoimmune thyroid disease susceptibility

Genetic susceptibility is an essential pathogenetic mechanism in autoimmune thyroid disease (AITD). MBL2 gene polymorphisms have been shown to play a vital role in the pathogenesis of multiple autoimmune disorders, but its contribution to AITD is unclear. The aim of this study was to assess the linkage between MBL2 gene polymorphisms and AITD susceptibility in a Chinese Han population. One thousand seven hundred sixty seven subjects consisting of 965 AITD patients and 802 controls from a Chinese Han population were enrolled in the case-control study. Four common single-nucleotide polymorphisms (SNPs) in the MBL2 gene were tested using high-throughput sequencing technology for sequence-based SNP genotyping. The allele and genotype distribution results showed that the minor alleles of rs198266, rs10824793, and rs4935046 were significantly lower in Hashimoto's thyroiditis (HT) patients than in healthy controls. In further genetic model analysis, the dominant models of rs1982266, rs10824793, and rs4935046 for MBL2 in the AITD group exhibited a lower risk of morbidity. Finally, we discovered that haplotype AAGC was associated with Graves' disease (GD), while AGC was associated with HT. Our study provides strong evidence for a genetic correlation between MBL2 and AITD, and the polymorphism of the MBL2 gene may be a protective factor for AITD, especially for HT. These findings can advance our understanding of the etiology of AITD, as well as provide guidance for prevention and intervention toward AITD.

GDF-15: A Potential Biomarker and Therapeutic Target in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a rheumatic disease. Growth differentiation factor 15 (GDF-15) is a member of transforming growth factor-β superfamily. To date, association of GDF-15 with SLE pathogenesis is not clarified. This study discussed GDF-15 serum levels and gene polymorphisms in SLE patients and lupus mouse model further demonstrated the role of GDF-15 in lupus development. We conducted two independent case-control studies for SLE patients. One is to evaluate serum levels of GDF-15 in 54 SLE patients and 90 healthy controls, and the other one is to analyze gene polymorphisms of GDF-15 in 289 SLE patients and 525 healthy controls. Serum levels of GDF-15 were detected by ELISA. GDF-15 gene polymorphisms (rs1055150, rs1058587, rs1059519, rs1059369, rs1227731, rs4808793, and rs16982345) were genotyped by the Kompetitive Allele-Specific PCR (KASP) method. Addition of recombinant GDF-15 into pristane-induced lupus mice evaluated histological and serological changes. Results showed that serum levels of GDF-15 were overexpressed in SLE patients and associated with disease activity. Polymorphisms rs1055150, rs1059369, rs1059519, and rs4808793 of GDF-15 gene were related to SLE risk. Lupus mice showed splenomegaly, severe histological scores, and high levels of autoantibodies [antinuclear antibodies (ANA) and total immunoglobulin G (IgG)], whereas administration of GDF-15 into lupus mice reduced the histological changes. Percentages of CD8⁺, CD11b⁺, CD19⁺, CD11C⁺ cells, T_H2 cells, and pro-inflammatory cytokines (IL-1β, IL-2, IL-4, IL-21, and IL-22) were reduced after GDF-15 treatment in lupus mice. In conclusion, GDF-15 was related to lupus pathogenesis and inhibited lupus development.